1. Field of the Invention
The present invention relates to a voltage supply circuit, more particularly to a voltage supply circuit capable of varying a voltage level of an output voltage.
2. Description of the Related Art
It is possible for an integrated circuit (IC) to operate improperly as a result of a large variation in temperature. For example, under normal conditions, an analog voltage of 1.9V may be supplied to an IC so that a certain pin outputs a desired voltage of 0.8V. However, if the integrated circuit is in a location where there are extremely cold temperatures, only 0.35V, for example, may be outputted through this particular pin, and it may not obtain the desired output voltage of 0.8V.
In the conventional circuit capable of solving this problem, a higher voltage level is supplied to the integrated circuit. However, the application of a high voltage comes at the expense of large power consumption and some other side effects in the integrated circuit.